Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add f-labs-io/agent-html-skills/plugin install html-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/f-labs-io/agent-html-skills/html-testing-checklist)<a href="https://agentmods.dev/skills/f-labs-io/agent-html-skills/html-testing-checklist"><img src="https://agentmods.dev/badge/skills/f-labs-io/agent-html-skills/html-testing-checklist/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/f-labs-io/agent-html-skills/html-testing-checklist"><img src="https://agentmods.dev/badge/skills/f-labs-io/agent-html-skills/html-testing-checklist.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00119 | $0.04920 |
| Opus 5 | $0.00060 | $0.02460 |
| Sonnet 5 | $0.00024 | $0.00984 |
| Haiku 4.5 | $0.00012 | $0.00492 |
Grade A, and why
html-testing-checklist scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
- **Exact inputs** — collect the real commands, URLs, sample payloads, test accounts, and expected outputs while you read. These become the embedded snippets; a step that says "call the endpoint" is a chore, a step with How it starts
The opening of the file, as written. The whole thing — 203 lines — stays where its author put it; the contents beside it link to each section on GitHub.
HTML Testing Checklist
"Please verify this works" usually arrives as a vague worry and leaves as a vague "looks fine". This skill turns it into an artifact: a thorough, walkable test plan — organized into the end-to-end flows a tester actually performs, each step carrying the exact command to run or input to type, what passing looks like, and a tick that advances a real progress bar. When the tester finishes (or gives up for the day), one Submit sends every step's pass/fail/blocked state and notes back to you, so failures become your next work queue instead of a Slack paragraph.
Pre-flight — run BEFORE writing the artifact
Invoke html-skills:html-skills-listen (Skill tool) first; it is idempotent. If it returns a URL, inject it verbatim as window.__CLAUDE_SUBMIT_URL__ in the HTML you are about to write, ?t= query string included (a local, single-session loopback handshake — not a credential). If it reported web/sandbox mode, leave that line out; submitToClaude then falls back to clipboard mode.
When to use this skill
- "Help me test / QA / verify this change (feature, PR, release, migration, bug-fix batch)"
- "What should I check before shipping?"
- "Write me a test plan / verification checklist / regression checklist"
- "I fixed these N bugs — how do I confirm they're all really fixed?"
- Handing work to a tester, reviewer, or teammate who needs to verify results without reverse-engineering the diff
If the user wants to edit or triage data rather than verify software, use html-throwaway-editor. If they want automated tests written, write tests — this skill is for the human verification pass that automated tests don't cover.
Tracker-backed checklists — bug lists are a natural input
A QA queue in an issue tracker is this skill at its best: "test the bugs marked check-QA on the board" should become a smart, two-way HTML checklist rendered from the tracker's real items, not a markdown dump of titles. The round trip runs through the same html-skills-listen receiver as everything else — the page never touches the tracker's API; you hold the credentials and do the writes.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago Changed · +13 lines · -92 tokens per session 8d7293e362c4
- 9d ago First seen · 190 lines · 211 tokens per session scan A 23b65e342f1d
html-testing-checklist is a skill published in the GitHub repository f-labs-io/agent-html-skills (55 stars, last pushed 6d ago), licensed MIT. It adds 119 tokens to every session and 4,920 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
dogfood
Systematically explore and test a mobile app on iOS/Android with agent-device to find bugs, UX issues, and other problems. Use when asked to dogfood, QA, exploratory test, find issues, bug hunt, or test this app on mobile.
test-warp-ui
Guides testing Warp UI features and changes using the computer use tool. Use this skill only when computer-use testing was requested (explicit request or accepted offer) and the computeruse tool is available to the agent. Covers launching Warp and verifying UI behavior.
test-electron-app
Drive the real running PostHog Electron app (live tRPC, workspace-server, real data) over CDP with agent-browser. Connect to the running app on port 9222, test desktop changes against a local Django stack, snapshot the accessibility tree, inspect network requests, and screenshot only when explicitly asked. Use when…
pyats-dynamic-test
Generate and execute deterministic pyATS aetest validation scripts - interface state, OSPF neighbors, BGP paths, ping matrices, and custom compliance tests. Use when writing a network test, validating post-change state, running pass/fail checks, or building automated regression tests.
test-loop
Plan, generate, and heal an executable E2E test suite from approved acceptance criteria (web and mobile).
playwright-cli
Automates browser interactions for testing and validating your own web applications using playwright-cli. Use when you need terminal-first browser control for navigation, form filling, screenshots, tracing, bound browser sessions, debugging, or generating Playwright test code. Only use against applications you own or…